Drill-striking mechanism for rock-drilling engines.



No. 794,930. PATENTED JULY 18, 1905.

L. DURKBE. DRILL STRIKING MBOHANISM FOR ROCK DRILLING ENGINES.

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No. 794,930. I PATEN TED JULY 18, 1905. L. DURKEEJ DRILL STRIKING MECHANISM FOR ROCK DRILLING. ENGINES.

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NITED STATES.

Patented July 18,1905.

PATENT OFFICE.

LAFAYETTE DURKEE, OF DENVER, COLORADO.

SPECIFICATION forming part of Letters Patent No. 794,930, dated July 18, 1905. Application filed June 7,1904. Serial No. 211,491.

To all whom, it may concern:

Be it known that I, LAFAYETTE DURKEE, a citizen of the United States of America, residing in the city and county of Denver and State of Colorado, have invented certain new and useful Improvements in Drill-Striking Mechanism for Rock-Drilling Engines; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in rock and coal cutting drill-bit hammer striking mechanisms for rock drilling engines, rock-channeling, rock-dressing, and coal-cutting machinery; and the objects of my invention are, first, to provide a rotary striking hammer; second-to provide a rotary striking disappearing hammer; third, to provide a rotary centrifugal drill-striking mechanism in which two or more hammers are employed and in which means are provided for locking the said hammers in a position of desired distance from the center of the disk,

disuse, so that one or more of them may be rendered inoperative; fourth, to provide a very simple durable high-speed centrifugal disappearing-hammer mechanism for drillbits that can be operated by any suitable motor or by hand-power and that will strike a very large number of blows per minute. I attain these objects by the mechanism illustrated in the accompanying drawings, in

. Which Figure 1 is a side elevation of my improved hammer striking mechanism arranged in operative striking relation to a rock-cutting drill-bit. Fig. 2 is a plan view of Fig. 1. Fig. 3 is an enlarged vertical longitudinal sectional view of my improved drill-striking mechanism in operative relation to a rockcntting drill-bit. Fig. 4 is a plan View of the drill-striking mechanism, the casing being omitted. Fig. 5 is a vertical sectional view through the drill-striking mechanism on the line 5 5 of Fig. 3. Fig. 6 is a sectional view through one of the flanges of the hammercarrying head. Fig. 7 is a perspective view of one of the hammers.

Fig. 8 is a rear elevation of a drill-striking mechanism positioncd upon a supporting-shell.

Similar numerals of reference refer to similar parts throughout the several views.

Referring to the drawings, the numeral 1 designates the hammer-carrying head, which "is composed of a disk 2, having an integral flange 3, and a flange 3", which is bolted to the side of the disk by bolts 4, which pierce through the disk. Countersunk holes are provided in the disk and flange for the head and nut of the bolts. The flanges of the disk are much larger in diameter than the disk. The disk is mounted on a shaft 6, which is supported in bearings 7, that are formed in a casing 8, that forms the supporting-frame of the drilling-engine. The casing is provided with a cover or cap 9, which is secured to the casing by bolts 10. In the periphery of the disk I form two recesses 11 and 12 on diametrically opposite sides of the disk, in each of which between the flanges l. pivot one end of two hammers 13 and 14 by the bolts 15 and 16. The disk may be made of any desired diameter and the hammers may be pivoted at any the distance being governed by the size and weight of the hammers and the weight of blow struck. Substantially the proportions illustrated are deemed to be the best for rock drilling engines, and these proportions may be followed in making hammer-heads and hammers for rock-drilling engines of different sizes. 1 preferably make the recesses in which the hammers are positioned extend rearward into the disk and form a pocket below the periphery of the disk, into which the heads of the hammers move when thrown back out of the path of the drill-bit, as will be explained more fully hereinafter.

The hammers are madeof a thickness to ill the space between the flanges,but loose enough to swing freely on their pivotal pins. The hammers consist of a hub portion 17, from which a substantially fan-shaped body por tion extends, onthe front end of which a hammer-striking end 19 projects beyond the front edge of the hammer. I preferably arrange the hammers so that their periphery comes nearly flush with the periphery of the flanges of the disk, when the hammers are thrown out to the limit of their striking distance. In the front wall of each hammeflrecess I secure a buffer 20, which may consist of a piece of leather or rubber, which I position to receive the blow of the hammer in case the drill-bit is not in position to be struck by the hammer the hood portion far enough to form a supporting-base for the motor and also projects far enough forward of the hood to provide a suitable support for the drill-bit-supporting mechanism. The casing is provided with ways 25, which fit slidably in the slideways 26, formed in a supporting-shell 27, which is provided with a depending fan-tailed hub 28, that is adapted to be secured to a suitable tripod or stoping-bar. Anut 28 is provided in the bottom of the ,rear end of the casing, and a suitable feed-screw, which I do not illustrate, is operatively connected to the nut and shell to feed the casing forward and backward in the shell. The front of the casing is arranged to support a rock-cutting drill-bit 29, which I preferably insert in a mandrel 30, which is loosely and slidably mounted in a sleeve 31, to which it is feathered by a key 32, thus securing it to the sleeve, so that both will rotate together, and permitting the mandrel independent reciprocative movement on the drill. The sleeve fits revolubly in a cylindrical portion 33 of the casing and extends beyond it into the hood a short distance, and on this end a circumferential row of gear-teeth 34 is formed, which may be connected to any suitable mechanism for intermittently rotating the sleeve and mandrel. The front end of the sleeve is provided with an enlarged flange which fits in a counterbore 35, formed in a cylinder head or cap that is bolted to the end of the cylindrical portion of the shell. The front, end of the mandrel is shorter than the sleeve, and a space is left at its front end in which a coiled expansive spring is placed, one end of which bears against the cylinderhead and the opposite end bears against the end of the mandrel. From the head portion of the mandrel a stem 36 extends rearward through and beyond a bearing-block 38, through which it extends slidably. This end of the mandrel is placed in striking relation to the hammers, as shown. Between the front end head portion of the mandrel and the bearing 38 and around the stem of the mandrel I place an expansive coiled spring 39. The front cylinder head or cap contains an axial aperture 40, and the mandrel also contains an lock in its socket one of the hammers out of striking relation to the drill-bit.

The operation of my improved hammerstriking mechanism is as follows: The hammer-head is rotated in the direction of the arrow 42, and where two hammers are used and a motor is applied the head can be rotated to strike from about eight hundred to twelve hundred blows per minute. As the hammers are pivoted between the axial center of the hammer-head and the periphery of its flanges,

they throw out the instant the disk is in motion and strike a very powerful blow, after which they instantly rebound or recede into their pockets from the end of the drill-bit, which they drive forward either against its forward spring or against rock if the machine is positioned in striking relation to rock. The rear spring of the mandrel simplyoperates to take the recoil of the drill-bit after striking rock and restore the resilient bal- I ance .of the mandrel. The hammer strikes so fast and the hammer-head rotates so fast that the hammers before they have time to fly back into their recesses are met by the rear "wall of the recesses; but as the pivotal centers of the hammers pass the end of the mandrel the hammers, even if they do not rebound, swing back on their pivots into their recess enough to clear the mandrel as the recesses move past the end of the mandrel. When the hammers do rebound into the recesses, they strike the buffers, and in case the mandrel is too far forward to receive their blows they strike against their front buffer and in both cases are cushioned and rebound without injury or objectionable noise. Hammer-heads may be made with three or more hammers in them, if desired, by making their hammer-heads larger in diameter; but one or two are suflicient for hand-operating drills, and one or two, or three at the most, will be all that will be required for the largest drilling-engines in use. The hammer-head may be mounted in ball-bearings, if desired, but turns very easily by hand in ordinary bearings, as the hammer-head rotates and maintains its velocity as easily as a fly-wheel.

My improved hammer-striking mechanism is very simple, durable, inexpensive, and can be applied to all kinds of rock-drilling machinery.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a drill-striking mechanism for rockdrills, a disk having recesses therein, hammers pivoted in said disk beyond its axial center, and arranged and adapted to swing out into drill-striking position by centrifugal force and to recede into said recesses out of drillstriking relation after a drill-striking stroke, suitable buffer devices in the opposite walls of said recesses arranged to receive the operative strokes of said hammers, and means for locking said hammers in said recesses in positions of disuse.

2. In a drill-striking mechanism for rockdrills, a pair of circular, rotatable plates, hav ing a circular block secured centrally between them, of less diameter than said plates, said block having a pair of oppositely-arranged recesses therein; centrifugally-operated hammers pivoted between said plates, within the recesses of said block; a buffer at the outer end of each of said recesses, to cushion the operating-blow of said hammers, and a buffer at the inner end of each of said recesses, to receive the recoil-blow of said hammers, as they recede into said recesses.

3. In a drill-striking mechanism for rockdrills, a pair of circular, rotatable, plates, having a circular block secured between them, of less diameter than said plates, said block having a pair of oppositely-arranged recesses therein; centrifugally-operated hammers pivoted between said plates, near the outer end of said recesses; bufiers at the outer ends of said recesses, to cushion the operating-blow of said hammers; buffers at the inner ends of said recesses, which receive the recoil-blow of said hammers; said inner buffers being so located with respect to the axis of said plates as that the recoil-blow of said hammers will not retard the rotation of said plates, and

means for locking one of said hammers in its recess, in an inoperative position.

4:. In a drill-striking mechanism for rockdrills, acircular plate, having an integral hub, which is provided with oppositely-positioned recesses, and a circular plate, similar to the first-mentioned plate, which is secured to the face of said hub; centrifugally-operated hammers pivoted between said plates, near the outer ends of said recesses; buffers to cushion the operating-blow of said hammers, and buffers to receive the recoil of said hammers, as they recede into their recesses.

5. In a drill-striking mechanism for rockdrills, a rotatable, flanged hub, having oppositely arranged recesses therein; centrifugally-operated hammers pivoted between said flanges, and within said recesses; buffers in said hub, which cushion the operating-blow of said hammers, and buffers in said hub, which receive the recoil of said hammers-as they recede into their recesses, in combination with a casing having an apertured, drillsupporting, lug, located between the flanges of said hub, but out of the path of said hammers, in their recoil position within the recesses of said hub, and a removable cap on the forward end of said casing, having a hole in axial line with the hole in said lug.

6. In a drill-striking mechanism for rockdrills, a rotatable, flanged, hub having oppositely-arranged recesses therein; centrifugall y-operated hammers, pivoted between said flanges, and within said recesses; and buffers in said hub-recesses for cushioning the operating and recoil blows of said hammers, in combination with a casing in which said flanged hub is mounted, having an apertured lug located between said flanges, but out of the path of the recoil position of said hammers; a removable cap on the forward end of said casing, having an aperture in axial line with the aperture of said lug; a shouldered mandrel, the rear end of which passes through the aperture in said lug, and is in the path of the striking end of said hammers; a coilspring on said mandrel between its shoulder and the lug, and a coiled spring between the forward end of said mandrel and said cap.

In testimony whereof I afIix my signaturein presence of twowitnesses.

LAFAYETTE DURKEE.

WVitnesses:

G. SARGENT ELLIOTT, BESSIE THOMPSON. 

